the observation was made with an automated video camera (KLEMOI in IMO Network),
the fireball showed intense, highspeed flickering
images can be seen here: http://forum.meteoros.de/viewtopic.php?f=8&t=57204 (german language meteor forum)
the video can be seen here: http://www.sternwarte-herne.de/misc/20170423_221204.AVI